The present invention relates to a dust trap and valve for controlling a flow through the dust trap, and more particularly, to an improved pressure balancing auxiliary valve located in the dust trap valve, which functions to reduce the force required to open the dust trap valve.
Dust traps of the type herein referred to have been used for years in collection systems such as bag houses--which in a typical installation comprise hundreds of vacuum cleaner type bags positioned in the flow of the output of a chimney or other flue device. The vacuum cleaner bags act to collect any impurities in the flow to provide clean air to this ecologically-minded world.
In a typical installation, the vacuum cleaner bags are arranged vertically in the flow path and then they are shaken (usually in a predetermined cycle) to permit the collected dust and other particles to drop to the bottom where they are collected in a dust trap.
The problem is to open the dust trap and remove the collected debris while the vacuum mechanism of the entire system is still in operation. This invention is directed toward that purpose.
In my previously issued U.S. Pat. No. 3,257,045 and entitled DUST TRAP AND VALVE THEREFOR, patented JUNE 21, 1966, a complete description of the operation of dust traps and valves is given, but basically, a valve body is mounted in the dust trap of an enclosed system in such a manner that it defines a valve seat and matching valve flap which closes the valve. In the cyclic cleaning of the system, the valve flap is opened to dump the contents collected in the valve, and then the valve flap is closed again.
It must be recognized that the valve seat and valve flap combination might close a flow path having an area of 200 square inches. Accordingly, the differential pressure across the valve flap, when the bag house is in operation, can require the application or use of a tremendous force to break the vacuum and pull the valve flap away from the valve seat to dump the contents.
It is the purpose of this invention to position an auxiliary valve in the valve flap to permit an initial balancing of pressure across the valve flap before it is opened thereby greatly reducing the force required to open the valve.
Therefore, it is the first object of this invention to provide an improved dust trap valve.
It is an additional object of this invention to provide a pressure release system for a dust trap valve, and,
It is still an additional object of this invention to provide an auxiliary release valve for a dust trap in which the pressure across the flap is balanced before the valve flap is moved from its closed position.